<?php
/**
 * XmuSlh, web platform of Student Association Federation of Xiamen University
 * 
 * Rewritting one or some pages of StatusNet. 
 * To get the original version, please visit <http://status.net/>.
 * 
 * StatusNet, the distributed open-source microblogging tool
 * 
 * LICENCE: This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * The main configuration entrance of the website! xmlslh!
 * 
 * 整个网站的配置, 以及相关初始化的入口.
 * 
 * @author		ytukie <ytukie@gmail.com>
 * @version		0.1
 */

// XmuSlh only.
if ( !defined('XMUSLH')) { exit(1); }

// The glabal variables.
global $config, $_server, $_path;

/**
 * Global configuration setup and menagement. 
 */
class XmuSlh
{
	protected static $have_config;
	protected static $is_api;
	/* 
	 * Currently, apis and plugins are not supported.
	 * 
	 * protected static $plugins = array();
	 */
	
	/**
	 * Configure and instantiate a plugin into the current configuration.
	 * Class definitions will be loaded from standard paths if necessary.
	 * Note that initialization events won't be fired until later.
	 * 
	 * @deprecated
	 */
	public static function addPlugin($name,
									 $attr = null) {}
									 
	/**
	 * Get a list of activated plugins in this process.
	 * 
	 * @deprecated
	 */
	public static function getActivePlugins() {}
	
	/**
	 * Initialize, or re-initialize, XmuSlh global configuration and //plugins.
	 * 
	 * If switching site configurations during script execution, be
	 * careful when working with leftover objects -- glabal settings
	 * affect many things and they may not behave as you expected.
	 */
	public static function init($server = null, 
								$path = null, 
								$conffile = null)
	{
		XmuSlh::initDefaults($server, $path);
		XmuSlh::loadConfigFile($conffile);
		
		// Load settings from database; note we need autoload for this.
		
		// deprecated
		// self::initPlugins();
	}
	
	/**
	 * TODO: Give the nickname of the site.
	 * Get identifier of the currently active site configuration
	 */
	public static function currentSite()
	{
		return 'XmuSlh';
	}
	
	/**
	 * TODO: What's this.
	 * 
	 * Change site configuration to site specified by nickname,
	 * if set up via XmuSlh_network. If not, sites other than
	 * the current will fail horribly.
	 * 
	 * TODO: XmuSlh_network is the what? storing in the database.
	 * 
	 * May throw exception or trigger a fatal error if the given site
	 * is missing or configured incorrectly.
	 */
	public static function switchSite($nickname)
	{
		if ($nickname == XmuSlh::currentSite()) {
			return true;
		}
		
		$sn = XmuSlh_network::staticGet('nickname', $nickname);
		if (empty($sn)) {
			return false;
			throw new Exception("No such site nickname '$nickname'");
		}
		
		$server = $sn->getServerName();
		XmuSlh::init($server);
	}
	
	/**
	 * Pull all local sites from xmuslh_network table.
	 * 
	 * Behavior undefined if site is not configured via XmuSlh_network.
	 */
	public static function findAllSites()
	{
		$sites = array();
		$sn = new XmuSlh_network();
		$sn->find();
		while ($sn->fetch()) {
			$sites[] = $sn->nickname;
		}
		return $sites;
	}
	
	/**
	 * Fire initialization events for all instantiated plugins.
	 * @deprecated
	 */
	protected static function initPlugins() {}
	
	/**
	 * Quick-check if configuration has been established.
	 * Useful for functions which may get used partway through
	 * initialization to back off from fancier things.
	 */
	public function haveConfig()
	{
		return self::$have_config;
	}
	
	public function isApi()
	{
		return self::$is_api;
	}
	
	public function setApi($mode)
	{
		self::$is_api = $mode;
	}
	
	/**
	 * TODO: Build the '/lib/slh_default.php';
	 * Build defalt configuration array
	 */
	protected static function defaultConfig()
	{
		global $_server, $_path;
		require(INSTALLDIR . '/lib/slh_default.php');
		return $default;
	}
	
	/**
	 * Establish default configuration based on given or default server and path
	 * Sets glbal $_server, $_path, $
	 */
	protected static function initDefaults($server, $path)
	{
		global $_server, $_path, $config;
		
		// Init the plugins
		// @deprecated.
		
		// try to figure out where we are. $server and $path
		// can be set by including module, else we guess based
		// on HTTP info.
		if (isset($server)) {
			$_server = $server;
		} else {
			$_server = array_key_exists('SERVER_NAME', $_SERVER) ?
				strtolower($_SERVER['SERVER_NAME']) : 
				null;
		}
		
		if (isset($path)) {
			$_path = $path;
		} else {
			$_path =(array_key_exists('SERVER_NAME', $_SERVER) && array_key_exists('SCRIPT_NAME', $_SERVER)) ?
				self::_sn_to_path($_SERVER['SCRIPT_NAME']) :
				null;
		}
		
		// Set config values initially to default values
		$default = self::defaultConfig();
		$config = $default;
		
		// default configuration, overwritten in config.php
		// Keep DB_DataObject's db config synced to ours..
		// The reference.
		$config['db'] = &PEAR::getStaticProperty('DB_DataObject', 'options');
		$config['db'] = $default['db'];
		
		// 
		
		if (function_exists('date_default_timezone_set')) {
			// work internally in UTC
			date_default_timezone_get('UTC');
		}
	}
	
	/**
	 * TODO: What is this.
	 * Server name to path?.
	 */
	protected function _sn_to_path($sn)
	{
		$past_root = substr($sn, 1);
		$last_slash = strrpos($past_root, '/');
		if ($last_slash > 0) {
			$p = substr($past_root, 0, $last_slash);
		} else {
			$p = '';
		}
		
		return $p;
	}
	
	/**
	 * Load the default or specified configuration file.
	 * Modifies global $config and 
	 * // may establish plugins.
	 */
	protected function loadConfigFile($conffile = null)
	{
		global $_server, $_path, $config;
		
		// From most general to most specific:
		// server-wide, then vhost-wide, then for a path,
		// finally for a dir (usually only need one of the last two.)
		if (isset($conffile)) {
			$config_files = array($conffile);
		} else {
			// deprecated the linux operation.
			
			$config_files[] = INSTALLDIR . '/config.php';
		}
		
		self::$have_config = false;
		
		foreach ($config_files as $_config_file) {
			if (@file_exists($_config_file)) {
				// Ignore 0-byte config files.
				if (filesize($_config_file) > 0) {
					include($_config_file);
					self::$have_config = true;
				}
			}
		}
		
		// Still no configuration.
		if ( !self::$have_config) {
			throw new NoConfigException("Not configuration file found.",
										$_config_file);
		}
		
		// Fixup for statusnet.ini?
		// deprecated currently.
		
		// TODO: What's below.
		if (array_key_exists('memcached', $config)) {
			if ($config['memcached']['enabled']) {
				// Add plugins?
			}
			
			if ( !empty($config['memcached']['base'])) {
				$config['cache']['base'] = $config['memcached']['base'];
			}
		}
	}
	
	/**
	 * Are we running from the web with HTTPS?
	 */
	static function isHTTPS()
	{
		// There are some exceptions to this; add them here!
		if (empty($_SERVER['HTTPS'])) {
			return false;
		} else {
			return $_SERVER['HTTPS'] !== 'off';
		}
	}
}

class NoConfigException extends Exception
{
	public $configFiles;
	
	function __construct($msg, $configFiles) {
		parent::__construct($msg);
		$this->configFiles = $configFiles;
	}
}

?>